Unless there are few other members need this, I won't add more config option. Sometime, you will have to customize code to meet your own need if needed.
We could not add config option for everything, otherwise, we will end up with thousands of config options.
I already gave instructions for modifying code here
joomdonation.com/forum/membership-pro-ge...bscriber.html#155246 in case someone needs it.
Regards,
Tuan